Traction bed construction

ABSTRACT

A bed construction having articulated body-supporting sections operable to enable a reclining person&#39;&#39;s back and knees to be elevated to flex the lumbar spine, the sections being adjustable toward and away from one another to subject the person&#39;&#39;s lumbar spine to traction.

United States Patent [1 1 Mikan TRACTION BED CONSTRUCTION [76] Inventor: Venzel R. Mikan, 205 Kennedy Rd.,

Saginaw, Mich. 48603 [451 July 2, 1974 3,404,679 10/1968 Bevilacqua... 128/71 Primary ExaminerLawrence W. Trapp Attorney, Agent, or Firm-Learrnan & McCulloch [5 7] ABSTRACT A bed construction having articulated bodysupporting sections operable to enable a reclining persons back and knees to be elevated to flex the lumbar spine, the sections being adjustable toward and away from one another to subject the persons lumbar spine to traction.

13 Claims, 4 Drawing Figures 1 TRACTION BED CONSTRUCTION This invention relates to a bed construction that is particularly adapted for the treatment of lumbar spinal disorders combining the medically accepted treatment methods of flexion and traction, and which also is adapted, without modification, for use as a conventional hospital bed.

In the treatment of low back conditions such as acute lumbo-sacral strain, spondylolisthesis, arthritis and disc syndrome, and the like, it is common practice among physicians to prescribe bed rest coupled with flexion of the lumbar spine and pelvic traction. When a patients lumbar spine is inflexion the posterior concavity of the lumbar spine is reduced, resulting in enlargement of the intervertebral foramina and opening of the articular facets to relieve compressive or irritative forces on the nerve roots. Traction then may be applied by means of a pelvic belt that may be connected to selected weights by means of ropes and pulleys.

Most, if not all, pelvic traction appliances are found in the physio-therapy departments of hospitals or in physicians offices. As a consequence, a patient subjected to pelvic traction is transferred promptly after a treatment with the result that the lumbar spine no longer remains in flexion. In many cases, benefit of the treatment thus is nullified to some extent.

Although traction often affords relief of the conditions for which it may be prescribed, the present methods of applying traction leave much to be desired. For example, it is difficult, if not impossible, to predict with any degree of accuracy the actual traction force that will be applied to a patient by a given weight. That is, the use of a weight of 40 pounds does not necessarily mean that the force exerted on the patients lumbar spine will be 40 pounds. The actual amount of force or pull exerted on the patients spine by a given weight is influenced by the weight ofthe patient and by the resistance of his body against the surface on which his body is supported. in practice, therefore, the amount of weight applied to a patient often may be insufficient to provide adequate traction to the lumbar spine or. alternatively, may be so great as to be uncomfortable to the patient and intolerable for any sustained length of time.

in many instances the intermittent application of traction of the lumbar spine could be beneficial to the patient, but not all of those devices heretofore available for applying traction to a patients lumbar spine have been capable of functioning intermittently without the services of an attendant. Requiring the services of an attendant, coupled with the inability of even the most skilled attendant to apply accurately a specific, predetermined traction force to the patients spine, has prevented known treatment devices from being as effective as they otherwise might be.

Many different types of beds that are claimed to be beneficial to persons having painful low back conditions have been proposed heretofore. Many such beds have included articulated sections that enable a person back to be inclined and his knees elevated. When the articulated sections of such beds are adjusted in this manner, however, traction cannot be applied to the lumbar spine.

All of the known articulated beds, when adjusted as described above, have one common characteristic, namely. that of supporting a person in such manner that the tuberosities of the ischii abut the section of the bed which effects elevation of the knees. As a consequence, significant anterior rotation of the pelvis is prevented and, therefore, there is no appreciable flexion of the lumbar spine.

Another problem encountered with articulated beds of known construction is that of inducing a desired amount of flexion in patients of different height. All such beds have hinged sections for supporting the legs of a patient, and such sections are so hinged as to permit the patients knees to bend. A shorter person, however, has a shorter femur than a taller person. As a consequence, a shorter person must be positioned closer to the foot end of the bed than a taller person if the shorter persons knees are to bridge the hinged sections. To flex the shorter persons spine, therefore, the hinged sections of the bed must be elevated to a higher level than is required for a taller person. The higher level of elevation required to flex the shorter persons spine can become quite uncomfortable after a relatively short period of time, thereby limiting the beneficial results of the flexion treatment.

An object of this invention is to provide a bed that is especially suited for the treatment of lumbar spinal conditions and which permits the combination of flexion and traction to be used.

Another object of the invention is to provide treatment. apparatus of the character referred to and wherein the amount of traction which may be applied is variable under the control of the patient so as to enable him to determine for himself the most effective and tolerable traction force.

A further object of the invention is to provide lumbar spine treatment apparatus which enables the use of traction force to be applied steadily or intermittently as desired.

Another object of the invention is to provide a treatment. device of the character referred to and which does not interfere with the beds being used in the conventional manner.

Another object of the invention is to provide a bed construction of the character described which may be manufactured to such dimensions as to be useful in the treatment of patients of greatly different height and size.

Other objects and advantages of the invention will be pointed out specifically or will become apparent from the following description when it is considered in conjunction with the appended claims and the accompanying drawings, in which:

FIG. 1 is a fragmentary, isometric view of a bed constructed in accordance with the invention;

FIG. 2 is a sectional view taken on the line 22 of FIG. 1 and showing in full lines the articulated bed sections in their lowermost positions and with the lower body-supporting sections in their retracted positions;

FIG. 3 is a view similar to FIG. 2 but showing the articulated bed sectionselevated and the lower bodysupporting sections in their extended positions; and

F IG. 4 is a fragmentary, isometric view of the driving mechanism by means of which the lower bodysupporting section may be reciprocated.

Apparatus constructed in accordance with the invention comprises a hospital type bed 1 having a supporting frame 2 comprising longitudinal and transverse frame members 3 and 4, respectively, supported on casters 5. Pivoted to the frame members 3 are crankshaped members 6 which are rockably connected to parallel rails 7 of a bed frame 8 of conventional construction and including outboard rails 9 supported from the rails 7 by cross-members 10. The members 6 may be rocked about their pivotal axes by conventional means (not shown) to raise and lower the bed frame 8 relative to the supporting frame 2.

At one end of the bed frame 8 is an upstanding headboard 11 and at the opposite end of the bed frame is an upstanding footboard 12, as is conventional. A panel 13 is pivoted at one end to the rails 9, as at 14, and overlies the upper surface of the bedframe 8 adjacent the head end thereof to provide a backsupporting section which may be swung from a lowered, horizontal position as shown in full lines in FIG. 2 to anyone of a number of upwardly inclined positions, as is shown in FIG. 3. Any one of a number of different devices for raising and lowering the back section 13 may be employed, but since such devices are conventional none is shown in the drawings. The bed construction as thus far described is conventional.

A bed frame 8 constructed in accordance with the invention includes a sub-frame 15 comprising longitudinal frame members 16 joined by cross bars 17. The sub-frame is slidablyfitted between the frame members 7 and the members 16 have flanges 18 which overlie the members 7 to provide support for the sub-frame.

Carried by the sub-frame 15 for movement therewith is a pair of rock arms 19 joined between their ends by a reinforcing bar 20. Adjacent the bar 20 each arm carries a bracket 21 through which extends a rock shaft 22 that is journaled in the frame members 16. Fixed to the supporting arms 19 and in overlying relation therewith is a lifter panel 23. To the bracket 21 is pivoted a considerably shorter strip or panel 24 which extends toward the head end of the bed frame and overlies a shelf 25 which is secured to and spans the bed frame members 9. The opposite end of the panel 23 is pivoted by means of a hinge 26 to one end of a panel 27, the opposite end of which is free and rests upon the frame members 7. Also pivoted to the panel 28 by means of a hinge 26 is a panel 28 which overlies the panel 23, but is longer than the latter so that its opposite end overlies the shelf 25.

Fixed to the bar 20 .is a depending link 29 to which is pivoted a threaded socket 30 that accommodates one end of a threaded shaft 31, the opposite end of which is splined and is accommodated in a correspondingly splined sleeve 32 which extends to the foot end of the bed and is connected to a crank (not shown) by means of which the sleeve 32 and the shaft 31 may be rotated. Rotation of the shaft 31 in one direction causes the panel 23 to be raised about the axis of the pivot 22 and, consequently, also causes the panel 27 to be raised so that the two panels 23 and 27 present an inverted V configuration. As the panels 23 and 27 are raised, the panel 28 also is raised, but since the panel 28 is longer than the panel 23, the degree of inclination of the panel 28 is less than that of the panel 23. The length of the panel 28 preferably corresponds to the length of the panel 27.

Means of conventional design and designated generally by the reference character 33 is provided for driving the subframe l5 fore and aft of the bed frame 8.

The driving means comprises a support 34 and it is carried by a frame member 35 fixed to and spanning the frame member 7. Secured to the member 35 is a sleeve 36 which mounts at one end thereof a gear reduction unit 37 and from which extends a threaded shaft 38 which passes through the sleeve 36 and is accommodated in a correspondingly threaded opening formed in a cross bar 39 that is fixed to the members 16 of the subframe. A reversible, electric motor 40 has its output shaft coupled to the gear reduction unit 37 so as to effect rotation in either one of two directions of the shaft 38.

The operation of the motor is controlledby a switch 41 mounted at one end of an insulated cable 42 which may be placed within easy reach of a patients hand. The switch has a three-position operating lever 43 having a central, neutral or off position from which it may be moved to either of two operating positions. In one operating position the subframe 15 is driven by the motor 40 toward the headboard l 1 so as to contract the overall length of the patient-supporting panels and in the other operating position the subframe is driven toward the footboard 12 so as to extend the overall length of the supporting panels. The motor may be stopped at any time by returning the lever 43 to its neutral position. i

The extent of movement of the subframe in either direction may be controlled by a conventional slip clutch (not shown) coupled between the shaft 38 and gear reduction unit 37, as will be understood.

Inasmuch as the several panel sections are movable relatively to one another, it is preferred that the conventional hospital mattress be replaced by thin, independent pads two of which are shown at 44 and 45 in dotted lines in FIGS. 2 and 3. The pad 44 should be of such length as to overlie the panel 13 and the pad 45 should be of such length as to overlie both of the panels 27 and 28. Suitable means (not shown) may be provided if necessary to prevent shifting of the pads 44 and 45 when their respective bed sections are elevated.

Ashas been stated hereinbefore, a bed constructed in accordance with the invention is designed to flexthe lumbar spine of a person occupying the bed. This is accomplished by positioning the patient on the bed in such manner that his knees bridge the hinge 26, followed by elevation of the back rest 13 and elevation of the panels 23 and 27 so as to effect corresponding elevation of the panel 28. The panels 13 and 28 thus present a V-shaped configuration having a low point 46. The extent of elevation of the panels 13 and 28 should be such that the superior crest of the ilium, i.e., the top of the pelvis, is at the low point 46 between the panels 13 and 28. When a person is so positioned, his lumbar space will bridge the low point 46 and his weight will cause the pelvis to be rocked anteriorly so as to reduce the posterior concavity of his spine. Thus, the lumbar spine of the person will be flexed.

Although the panel 28 is of fixed length the distance from the lower end of the panel 13 to a vertical plane passing through the hinge 26 decreases as the panel 28 is elevated. As a consequence, both tall and short persons may be subjected to treatment by means of the same bed. Although treatment of a shorter person may require elevation of the panel 28 to a greater height than that required for treatment of a taller person. the degree of inclination of the panel 28 always is less than that of the section 23, thereby avoiding the necessity of having to raise the shorter persons back and knees to positions which would be uncomfortable over sustained periods of time.

When a patient is positioned on the bed with his lumbar spine flexed, traction may be applied to the patient by means of a pelvic traction belt (not shown) to which one end of a strap (not shown) may be fastened, the distal end of the strap being anchored to the subframe 15. The pelvic belt and the anchor strap maintain the patients pelvis in the proper position relative to the panels 13 and 28 and prevents slipping. A thoracic belt (not shown) also may be fitted onto the patient, the thoracic belt being anchored by a pair of straps (not shown) that are secured to the underside of the panel 13. With the pelvic and thoracic belts fitted to the patient and anchored to the bed, the motor 40 may be driven in a direction to cause the panel 28 to. move toward-the foot end of the bed, thereby applying substantial pelvic traction to the patient. As the panel 28 moves away from the panel 13, the low point 46 remains at the same level even though its fore and aft length increases.

The application of traction may be steady or intermittent. That is, the panel 28 may be advanced a desired distance by operation of the motor 40 and the latter stopped, whereupon the panel 28 will remain in its advanced position so as to enable a steady traction force to be applied to the patients spine. Alternatively, the panel 28 may be successively advanced and retracted, under the control of the switch 41, so as to apply intermittent traction to the pelvis.

By adjusting the elevations of the panels 13 and 28 the extent of flexion may be varied so as to enable a patient to maintain his lumbar spine flexed following the r ction treatment.

lf the patient is hospitalized, and if a bed constructed according to the invention serves both as his traction apparatus and as his hospital bed, the patient may remain in a position with his spine flexed for as long as is desired following the traction treatment. This quite often will have advantageous therapeutic effects. At any time. however. the panels may be lowered to their horizontal positions in which the panels 13, 27, and 28 extend in prolongation of each other and thereby permit the bed to be used as a conventional hospital bed. This will necessitate the use of an additional pad, similar to the pads 44 and 45, to enable the full length of the panels to be covered.

Apparatus constructed in accordance with the invention is not a panacea for all back conditions. For example, many patients suffering from low back pain will un-' dergo a marked increase of pain when the lumbar spine is flexed. Moreover. some patients experience pain when only a small amount of traction is applied. Obviously, the bed of the present invention should not be prescribed for traction or flexion treatment of such patients, but the knowledge that a patient cannot tolerate flexion or traction of the lumbar spine is of value to a physician in diagnosing the patients disorder.

The disclosed embodiment is representative of the presently preferred form of the invention, but is intended to be illustrative rather than definitive thereof. The invention is defined in the claims.

I claim:

1. A bed construction comprising a back-support panel; a leg-support panel; means mounting each of said panels for swinging movements from a substantially horizontal position in which said panels extend in prolongation of one another to a position in which said panels present a V-shaped configuration. and return;

and means formoving one of said panels toward and away from the other.

2. A bed construction according to claim 1 wherein said mounting means are independent of one another whereby each of said panels is swingable independently of the other.

3. A bed construction according to claim 1 wherein said one of said panels is said leg-support panel.

4. A bed construction according to claim 3 wherein that end of said leg-support panel adjacent said backsupport panel is free, and including means for supporting said free end of said leg-support panel.

5. A bed construction comprising a frame; a backrest pivoted to said frame for swinging movements from a substantially horizontal position to an upwardly inclined position; a subframe carried by said frame for fore and aft movements relative thereto; a thigh supporting member; means connecting one end of said member to said subframe for movements therewith and for swinging movements from a substantially horizontal position to an upwardly inclined position whereby said member and said backrest, when in their inclined positions, present a substantially V-shaped configuration; and means for moving said subframe fore and aft relatively to said frame whereby said member may move toward and away from said backrest.

6. The construction set forth in claim 5 including a substantially horizontal shelf for supporting the other end of said member.

7. The construction set forth in claim 5 including lower leg supporting means pivoted to said one end of said member for swinging movements from a substantially horizontal position to an upwardly inclined position, whereby said supporting means and said member, when inclined. present an inverted, substantially V- shaped configuration.

8. The construction set forth in claim 5 wherein the means connecting said one end of said member to said sub-frame comprises lifter means pivoted to said one end of said member and pivoted to said sub-frame.

9. The construction set forth in claim 8 wherein the fore and aft length of said member is greater than the fore and aft length of said lifter means.

10. A bed construction comprising a frame having head and foot ends; a sub-frame carried by said frame for fore and aft movements relative thereto; a back support adjacent the head end of said frame; means pivoting one end of said back support on said frame for swinging movements between raised and lowered positions; a leg support between said head support and the foot end of said frame with one end of said leg support confronting said one end of said-back support; lifter means pivotally connecting the other end of said leg support to said sub-frame for swinging movements of said leg support between raised and lowered positions, said one end of said leg support being free; and means for moving said sub-frame fore and aft of said frame whereby said leg support moves toward and away from said head support.

11. The construction set forth in claim 10 including a lower leg support interposed between said leg support and the foot end of said frame, said lower leg support being pivoted at one end thereof to said other end of said leg support and being free at its other end.

12. The construction set forth. in claim 11 wherein said leg support has a fore and aft length greater than that of said lifter means.

frame includes a shelf member extending transversely of said frame and underlying said one end of said leg support.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 82l 953 Dated July 2 1974 Inventor(s) Venzel R. Mikan It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown .below:

line 47, after "traction" change "of" to Column 1,

Column 3, line 41, after "panel" change "28" to 23 Column 4, line 51, change first word "space" to spine Signed and sealed this 24th day of September 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. Attesting Officer C. MARSHALL DANN Commissioner of Patents FORM PO-105O (10-69) USCOMM-DC 00376-P69 u. 5' covzmmzm "mums OFFICE: 190 o-ass-su. 

1. A bed construction comprising a back-support panel; a legsupport panel; means mounting each of said panels for swinging movements from a substantially horizontal position in which said panels extend in prolongation of one another to a position in which said panels present a V-shaped configuration, and return; and means for moving one of said panels toward and away from the other.
 2. A bed construction according to claim 1 wherein said mounting means are independent of one another whereby each of said panels is swingable independently of the other.
 3. A bed construction according to claim 1 wherein said one of said panels is said leg-support panel.
 4. A bed construction according to claim 3 wherein that end of said leg-support panel adjacent said backsupport panel is free, and including means for supporting said free end of said leg-support panel.
 5. A bed construction comprising a frame; a backrest pivoted to said frame for swinging movements from a substantially horizontal position to an upwardly inclined position; a subframe carried by said frame for fore and aft movements relative thereto; a thigh supporting member; means connecting one end of said member to said subframe for movements therewith and for swinging movements from a substantially horizontal position to an upwardly inclined position whereby said member and said backrest, when in their inclined positions, present a substantially V-shaped configuration; and means for moving said subframe fore and aft relatively to said frame whereby said member may move toward and away from said backrest.
 6. The construction set forth in claim 5 including a substantially horizontal shelf for supporting the other end of said member.
 7. The construction set forth in claim 5 including lower leg supporting means pivoted to said one end of said member for swinging movements from a substantially horizontal position to an upwardly inclined position, whereby said supporting means and said member, when inclined, present an inverted, substantially V-shaped configuration.
 8. The construction set forth in claim 5 wherein the means connecting said one end of said member to said sub-frame comprises lifter means pivoted to said one end of said member and pivoted to said sub-frame.
 9. The construction set forth in claim 8 wherein the fore and aft length of said member is greater than the fore and aft length of said lifter means.
 10. A bed construction comprising a frame having head and foot ends; a sub-frame carried by said frame for fore and aft movements relative thereto; a back support adjacent the head end of said frame; means pivoting one end of said back support on said frame for swinging movements between raised and lowered positions; a leg support between said head support and the foot end of said frame with one end of said leg support confronting said one end of said back support; lifter means pivotally connecting the other end of said leg support to said sub-frame for swinging movements of said leg support between raised and lowered positions, said one end of said leg support being free; and means for moving said sub-frame fore and aft of said frame whereby said leg support moves toward and away from said head support.
 11. The construction set forth in claim 10 including a lower leg support interposed between said leg support and the foot end of said frame, said lower leg support being pivoted at one end thereof to said other end of said leg support and being free at its other end.
 12. The construction set forth in claim 11 wherein said leg support has a fore and aft length greater than that of said lifter means.
 13. The construction set forth in claim 10 wherein said back support and said leg support when in their raised positions present a V-shaped configuration with the low point thereof at the confronting ends of said back support and said leg support, and wherein said frame includes a shelf member extending transversely of said frame and underlying said one end of said leg support. 